Instructables

A few years ago I bought a VPX tool system. For $50 it had a powered screwdriver, a reciprocating saw, a drill and a light plus a charger and one battery. I use the power driver the most as it has a very low profile and can get into some tight spaces. I added another charger and three batteries to the system. This year they all conked out. I requested testing info from B&D and got a reply of  "Plug the battery into the charger, wait 30 min. and feel to see if its warm". This didn't answer my question at all, so I started my own investigation into the testing methods.

Tools needed: small straight blade screwdriver to undo the clips, soldering iron, Volt/Ohm meter, needle-nose pliers.

To test the battery set the VOM to DC Volts and check between the two larger terminals (A and B). You should get around 6VDC, but a reading is what you are looking for. If its 3VDC or less, you need to check both of the cells to find out which is bad. With the pack facing you the three small terminals should be on the bottom. Use terminals A and E, then B and E. They should read around 3VDC each. If not one or both of the cells are bad. They will also spot weld terminals to the battery for just a few pennies more. This will come in handy when you rebuild your pack.

To replace your pack with a new one will cost you $20 and up. This site (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200598283959+&clk_rvr_id=248358621899&item=200598283959) has a four pack for around $10 at the time of this posting. You can find other deals by searching for A123 batteries. THEY DO MAKE A NON-RECHARGEABLE A123 battery, so be carful you get the right kind.

To start. remove the label from the battery. it should come off in one piece. You can put it back on later if you store it somewhere the tacky side doesn't get damaged, but you don't need it after the rebuild so don't worry if it gets damaged. With the label removed you can see the clips that hold the pack together. You only need to un-clip the side with the terminals by lifting the tab up with the small pliers.

The battery and terminals should just slip out. DON'T TEAR OFF THE WRAPPER! Once the wires are cut the wrapper will slip off and can be reused. The welds can be pulled off with the pliers, but if you buy the ones with terminals you can just clip them. Remember you will be soldering these wires back on to a new one, so cut them as close as you can.




 
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Step 1: Testing


Tools needed: small straight blade screwdriver to undo the clips, soldering iron, Volt/Ohm meter, needle-nose pliers.

To test the battery set the VOM to DC Volts and check between the two larger terminals (A and B). You should get around 6VDC, but a reading is what you are looking for. If its 3VDC or less, you need to check both of the cells to find out which is bad. With the pack facing you the three small terminals should be on the bottom. Use terminals A and E, then B and E. They should read around 3VDC each. If not one or both of the cells are bad. They will also spot weld terminals to the battery for just a few pennies more. This will come in handy when you rebuild your pack.


Step 2: Disassembly

To start the rebuild/repair, pull off the wrapper from the pack. It should come off in one piece. Save it for replacement after the repair.
There are two clips holding the terminal end on the pack, pry them up (Not to hard, you need this piece intact.) I had to use a small flat blade for this step.

Pull the terminals and batteries out. Clip the wires as close to the terminals as possible. I had four packs and only two good batteries. In this case I removed only the bad cell from one and a good cell from another to take its place.


Step 3: Repair

Picture of Repair
Observing the polarity, connect battery. If you got new ones with the tabs, this is simple. Just solder the leads to the tabs. Make sure it will fit back into the housing when done. If you are just replacing one cell like I did, you need to solder iyt in place. I was going to use Conductive Glue, but was worried the resistance might be too much. For a tempory fix I used Duct Tape to hold the leads on while I finished the job at hand. I used the Gorilla brand because it's a heavy duty tape with extra holding power. If you have never use this brand, do your self a favor and try it out. It's weather and water proof. I have used it on some outside projects and some of it has been there for over two years, still holding strong. So far I have been using this rig for a few days with no problems.

Step 4: Reassembly

Slide the completed unit back in it's housing. If you saved the wrapper you can replace it. I'm a bit lazy, so I left mine off.

Charge it up and you'r ready to go.
Thanks for the posting. Whole new world for me. What is the thermister for? It's not mentioned as a needed tool in intro. I just opened two battery packs using your instructions and after testing found a good and bad in each, swapped out the bad with a good. I pried off the two whole tabs from the bad one still attached to the wire. Tried to solder old tab to top and bottom of substitute battery without much success so taped the tabs on the substitute battery with Gorilla tape, reassembled it in case, put it in charger and it charged up just fine. I couldn't get the cardboard wrapper back on with the tape, so reassembled it without a wrapper on the newly added, taped one. Seems fine. How important is the wrapper? Also, ordered set of 8 new batteries with tabs and they asked about orientation for the tabs. I wasn't sure what to say??? Any thoughts??? Also, if the tape holds up, it will be easier to rebuild in the future without the solder, just keep re-using old tabs attached to wiring. What do you think?
redkcir (author)  hammermomma1 year ago
Sorry it took so long to answer you.
The thermistor is a device like a fuse but works on heat. Safety feature. I think the wrapper just keeps some distance between the batteries. Heat issue maybe? As for tab orientation see the attached pictures. When the polarity is +-+- the bottom tabs are together it leaves the top tabs facing opposite directions. A resistor and white wire attach to the bottom pair which leaves the black and red wire for the top tabs.
DSCF2049.JPG
pfred23 years ago
Are lithium-ion batteries more explosive than other kinds? I've soldered to lots of different kinds of batteries but not a li-on one yet. I scuff them with emery paper, tin them quickly, then solder a tinned wire to it, never had a problem. I have the whole VPX line except for the USB charger air compressor thing. I thought it was a bit too silly. I bought it all at a B&D outlet when they were dumping the line

The flashlight is really cool! I have the 2 battery 14.4V drill, the same kit you have, and the 7.2V clutch keyless chuck drill too. Along with 4 batteries and 2 dual chargers. So yeah when my batteries go I'm going to be hurting!

I think I spend too much time at the B&D outlet

http://i.imgur.com/RCcBv.jpg
redkcir (author)  pfred23 years ago
I'm not sure. But to avoid welding (don't have that capability right now) I sometimes use metallic glue instead of spring load battery holders. I have one of these units I put together with Gorilla duct tape (it's a lot stronger that regular tape and is weatherproof) to hold the connection wire to the battery and it's been running for months now. I've recharged it several times and it still going strong.
pfred2 redkcir3 years ago
I have a few welders, I use a MIG to zap nicad batteries. Works sometimes. I'm pretty sure it doesn't work with lithium ion batteries at all though. There is even an article about doing it here:

http://www.instructables.com/id/Revive-Nicad-Batteries-by-Zapping-with-a-Welder/

I just did a pack that was totally dead and reading faulty in my charger but now it is charging up.

Soldering is another story. When I solder to a battery I do it fast.

redkcir (author)  pfred23 years ago
I have read that there need to be a bit of power left before you can recharge one, but that you can jump start it some how. It involved tricking the charger into thinking the battery had more power than it did. I can solder as well, but wasn't sure about using that method because of the amount of time it would take to get the battery hot enough for the solder to work. Thats why I tracked down where to get the batteries from. The pre-tabbing was just a bonus find.
pfred2 redkcir3 years ago
Tabs are better than soldering directly to batteries. I've never had a problem soldering right to a battery though. Like I said I do it so fast they do not have time to heat up on more than just the metal surface. Method is as I said, prepare the surface with emery cloth, tin, then solder a tinned wire to the tinned spot after the battery has cooled down again. Works every time. I'm sure of it.